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HAWAH  AGRICULTURAL  EXPERIMENT  STATION 
HONOLULU,  HAWAH 

Under  the  superrision  of  the 
UNITED  STATES  DEPARTMENT  OF  AGRICULTURE 


BULLETIN  No.  51 


THE  GUATEMALAN  AVOCADO 
IN  HAWAII 


BT 


W.  T.  POPE,  Horticulturist 


Issued  August  16, 1924. 


\    > 


WASmNGTON 

GOVERNMENT  PRINTING  OFFICE 

1924 


HAWAII  AGRICULTURAL  EXPERIMENT  STATION,  HONOLULU 


[Under  the  supervision  of  the  Office  of  Experiment  Stations,  United  States  Department  of 

Agriculture.] 

E.  W.  Allen,  Chief,  Office  of  Ea?periment  Stations. 

Walteb  H.  Evans,  Chief,  Divisiofi  of  Insular  Stations,  Office  of  Experiment 
Stations. 


STATION  STAFF. 

J.  M.  Westgate,  Agronomist  in  Charge. 

W.  T.  Pope,  Horticulturist. 

H.  L.  Chung,  Specialist  in  Tropical  Agronomy. 

J.  C.  RiPPERTON,  Chemist. 

R.  A.  GoFF,  In  Charge  of  Glenwood  Substation  and  Extension  Agent  for  the 

Island  of  Haivaii. 
Nellie  A.  Russell,  Collaborator  in  Home  Demonstration  Work.^ 
Mabel  Gbeene,  Boys^  and  Girls'  Club  Leader. 


Api>ointed  on  part-time  basis. 


HAW 

All  AGRICULTURAL  EXPERIMExNT 
HONOLULU,  HAWAII 

Under  the  superyision  of  the 
UNITED  STATES  DEPARTMENT  OF  AGRICULT 

STATION 

UBE 

BULLETIN  No.  51 

Washington, 

D.  C. 

August  16, 

1924 

THE    GUATEMALAN   AVOCADO   IN   HAWAII, 


W.  T.  Pope.  Horticulturist, 


CONTENTS. 


Introduction 

History  in   Hawaii 

Nomenclature 

Characters 

Pronagation 

The  orchard 

Cultural  requirements- 


Page. 


Page. 


The  crop 

Yields 

Control  of  insect  enemie.'«_ 
Composition  of  the  fruit- 
Uses 

Experiments  in  progress _- 
Description   of   varieties.. 


INTRODUCTION. 

The  Hawaiian  Islands,  with  their  many  cool  yet  frostless  localities 
at  vaiying  elevations,  uniformity  of  rainfall,  and  well-drained  soils, 
are  adapted  to  the  culture  of  the  avocado.  The  higher  elevations  are 
particularly  suited  to  the  gi'owing  of  the  Guatemalan  avocado,  which 
originated  tmder  similar  conditions  in  the  country  of  its  name.  This 
race  of  avocados  has  well-defined  advantages  over  practically  all 
other  tree  fruits  in  the  Territory.  In  cultural  requirements  it  is 
suited  to  considerable  areas  that  are  not  now  utilized  for  any  other 
cultivated  crops.  At  an  early  age  it  produces  crops  that  mature  in 
the  winter  season  when  the  summer  or  "West  Indian  avocados  are  not 
in  market.  The  fruit  has  a  rind  which  protects  it  from  attacks  of  the 
Mediterranean  fruit  fly  (Ceratitis  caqntata).^  The  fruit  is  character- 
ized by  its  firm  pulp,  tight-fitting  seed,  and  hard  rind.  It  has  a  high 
food  value  and  is  considered  b\  some  horticulturists  one  of  the  great- 
est undeveloped  tropical  sources  of  food.^ 

The  data  presented  in  this  bulletin  represent  the  results  of  20 
years'  work  with  the  Guatemalan  avocado  at  the  Hawaii  Experiment 
Station.  The  fruit  has  unlimited  marketing  possibilities  on  the  main- 
land of  the  States  and  in  other  countries,  as  well  as  in  Hawaii,  and 
its  cultivation  should  be  extended. 


1  TT.  S.  Dept.  Agr.  Bui.  586.  The  Mediterranean  fruit  fly  in  Hawaii,  p.  44. 

2  Popenoe,  Wilson,     Manual  of  tropical  and  subtropical  fruits,  p.  9. 


84456°— 24- 


2  BULLETIN    51,   HAWAII   EXPERIMENT   STATION. 

HISTORY  IN  HAWAII. 

According  to  records  published  by  the  Koyal  Agricultural  So- 
ciety,-^ the  Guatemalan  avocado  Tvas  introduced  into  Hawaii  probably 
early  in  the  nineteenth  century  by  Don  Francisco  de  Paula  Marin, 
a  Spanish  horticulturist.  Published  reports  give  Don  Marin  credit 
for  having  introduced  many  other  valuable  economic  plants  which 
he  grew  in  his  garden  in  Pauoa  Valley,  and  in  his  "  ka  pa  waina," 
or -vineyard  place,  near  what  is  now  known  as  Vineyard  Street, 
Honolulu. 

Dr.  William  T.  Brigham,  of  Honolulu,  states  that  in  the  private 
journal  of  Doctor  Bloxam,  the  naturalist  of  the  Blonde^  the  British 
vessel  which  brought  the  remains  of  Kamehameha  II  and  his  wife 
to  Honolulu,  it  is  stated  that  the  avocado  and  other  fruits  were 
found  growing  in  Honolulu  and  vicinity  in  1826.  Very  likely  some 
of  the  fruit  mentioned  included  introductions  by  Don  Marin.  Doctor 
Brigham  further  states  that  while  botanizing  in  the  Pauoa  Valley 
in  1855  he  found  avocado  trees  bearing  round,  greenish-colored  fruits 
which  had  rough  rind,  large  seed,  and  rather  fibrous  flesh  that  was 
not  generally  liked  by  those  who  tried  it.  The  description  of  the 
fruit  corresponds  with  that  of  the  Guatemalan  avocados  examined 
by  the  writer  in  the  Pauoa  Valley  in  1902. 

According  to  the  statement  of  Judge  Sanford  P.  Dole,  a  former 
governor  of  the  Territory ,  the  Guatemalan  avocado^  has  been  growing 
in  the  valley  of  Pauoa  for  many  years,  but  it  is  not  as  well  known 
or  as  well  liked  as  are  the  West  Indian  varieties  which  grow  in 
other  parts  of  the  Territory.  Some  of  these  facts  would  seem  to 
indicate  that  Don  Marin  brought  his  original  seedlings  from  the 
west  coast  region  of  Central  America.  Tlieir  failure  to  become 
generally  distributed  is  likely  due  to  the  poor  quality  of  the  fruit, 
improvement  by  cross-pollination  with  good  varieties  not  being 
possible  in  the  small  valley  of  Pauoa,*  and  to  the  early  introductions 
of  better  varieties  of  the  West  Indian  race  into  other  parts  of 
Hawaii. 

In  1853  the  United  States  ship  of  war  Portsmouth  stopped  at  the 
ports  of  Hilo,  Lahaina,  and  Honolulu,  leaving  seedling  avocado 
trees  from  Central  America.  It  is  believed  that  this  introduction 
was  the  fii^st  to  have  a  wide  influence  upon  the  cultivation  and  dis- 
tribution of  the  avocado  in  Hawaii. 

In  1895  Rear  Admiral  L.  A.  Beardslee,  commander  of  the  Pacific 
naval  forces  of  the  United  States,  with  headquarters  at  San  Francisco, 
came  to  Honolulu  on  the  flagship  Philadelphia.  It  was  on  this  visit 
that  he  introduced  several  Guatemalan  avocado  seedlings,  the  fruit 
having  been  brought  to  him  in  San  Francisco  just  previous  to  his 
sailing  for  the  Hawaiian  Islands.  On  his  arrival  in  Honolulu, 
January  30,  1895,  he  gave  three  of  the  germinating  seeds,  wrapped 
in  moist  cotton,  to  his  friends  Mrs.  E.  K.  Wilder,  Judge  H.  A. 
Wiedemann,  and  Judge  J.  W.  Kalua. 

The  seed  given  to  Mrs.  Wilder  was  planted  at  her  Esbank  home 
in  Nuuanu  Valley,  where  the  tree  fruited  and  after  a  few  years 
died.    It  is  thought  that  none  of  the  seed  of  this  tree  was  planted. 

8  An  organization  which  flourished  on  the  islands  about  the  middle  of  the  nineteenth 
century. 

*  The  writer  has  found  no  evidence  of  the  Guatemalan  avocado  of  Pauoa  Valley  having 
influenced  the  growing  or  the  quality  of  the  avocado  fruit  in  other  parts  of  the  Territory. 


THE   GUATEMALAN   AVOCADO    IN    HAWAII.  3 

The  seed  given  to  Judge  Wiedemann  was  grown  on  liis  premises 
in  the  Punahou  district  of  Honohihi.  1402  Punahou  Street,  now  occu- 
pied by  the  Macdonald  Hotel.  When  the  tree  began  to  attract 
attention  as  a  prohfic  bearer,  it  became  known  as  the  "  Macdonald 
avocado,"  instead  of  the  Wiedemann,  as  probably  it  should  have  been 
called.  (Plate  I.)  The  tree  produces  very  rough,  spherical,  hard- 
shelled  fruit  in  winter,  and  the  flesh  is  rich  and  of  excellent  flavor. 
Many  trees  have  been  propagated  from  buds  taken  from  the  Mac- 
donald, and  it  is  now  recognized  as  a  distinct  variety  of  Guatemalan- 
Hawaiian  origin.  Tlie  most  interesting  and  valuable  feature  asso- 
ciated with  its  development  is  the  superiority  of  a  number  of  the 
progeny  to  the  parent  in  nature  of  gi'owth  and  quality  of  fruit. 

The  seed  received  by  Judge  Kalua  was  taken  to  Wailuku,  ]\Iaui, 
where  the  tree  is  still  growing.  It  also  is  a  vigorous,  prolific  speci- 
men which  matures  its  fruit  during  the  winter  months.  Several 
seedlings  grown  from  the  tree  have  excellent  qualities  and  are  de- 
scribed elsewhere  in  this  bulletin.  The  station  has  propagated  trees 
from  buds  taken  from  the  Kalua  Guatemalan  avocado. 

A  number  of  new  varieties  of  the  Guatemalan  avocado  trees  Avere 
received  from  the  Office  of  Foreign  Seed  and  Plant  Introduction  of 
the  United  States  Department  of  Agi'iculture  in  1919,  and  many 
have  been  received  since.  They  represent  a  part  of  the  valuable 
collection  made  by  Wilson  Popenoe,  agricultural  explorer,  who  spent 
many  months  in  carefully  exploring  the  highlands  of  Guatemala  in 
search  of  the  most  promising  types  of  avocados.  These  introduc- 
tions are  now  growing  at  the  Tantalus  substation. 

NOMENCLATURE. 

COMMON  NAMES. 

The  avocado  was  probably  first  referred  to  in  literature  as  the 
'*  pear  "  or  peral  by  Gonzalo  Hernandez  de  Oviedo  in  his  report  to 
Charles  V  of  Spain  in  1526.  He  states,  however,  that  the  fruit  is  a 
pear  in  form  but  in  nothing  else.^  Since  that  time  the  avocado  has 
been  called  by  numerous  other  names.  Among  English-speaking 
people  the  misnomer  "  alligator  pear  "  is  applied  to  it.  Alphonse 
De  Candolle,  in  his  "  Origin  of  Cultivated  Plants,"  states  that  the 
name  "  avocado  *'  is  a  corruption  of  the  Mexican  ahiiacate^  or  agiia- 
cate.  which  in  turn,  Popenoe  says,  is  an  adaptation  of  the  Aztec 
ahuacatl.  In  Chile,  Peru,  Ecuador,  and  in  parts  of  Central  America 
the  fruit  is  commonly  known  as  the  j^alta. 

BOTANICAL  STATUS. 

The  avocado  was  first  described  by  Linnaeus  in  1753  under  the  bo- 
tanical name  of  Laurus  persea.  Miller,  in  1768,  placed  it  under  the 
genus  Persea  and  species  americana.  The  genus  Persea  belongs  to 
the  laurel  family  (Laurace^)  and  is  related  to  the  cinnamon,  cam- 
phor, sassafras,  and  California  bay.  Persea  americana  is  also  known 
by  some  horticulturists  as  P.  gratissima.  P.  americana  has  be- 
come the  most  generally  accepted  name  for  the  avocado,  and  under 
it  may  be  listed  all  of  the  varieties  known  horticulturally  as 
belonging  to  the  West  Indian.  Guatemalan,  and  Mexican  races.    The 


'"  Sumario  de  la  natural  hlistoria  de  las  Indias.     (Biblioteca  de  autores  espauoles,  histori- 
adores  primitivos  de  Indias,  Madrid,  1852.) 


4  BULLETIN    51,   HAWAII   EXPERIMENT   STATION. 

characters  serving  to  distinguish  tlie  different  races  horticulturally 
are  shown  in  the  following  key : 

(a)  West    Indian   race.     Summer   and   fall    ripening;    fruit   large;    rind 
leathery  and  not  more  than  one-sixteenth  inch  in  thickness. 

(ft)   Guatemalan   race.     Winter    and    spring   maturing;    fruit   large;   rind 
one-sixteenth  to  one-fourth  inch  in  thickness ;  woody  in  texture. 

(c)   Mexican  race.     Leaves  small  and  anise  scented;  fruit  small  and  thin- 
skinned. 

CHARACTERS. 

Habits  of  growth. — The  Guatemalan  avocado  is  exceedingly  vari- 
able in  its  habits  of  growth,  ranging  in  size  in  its  native  land  from 
mere  bushes  to  trees  attaining  a  height  of  between  60  and  80  feet 
with  trunks  3  to  4  feet  in  diameter.  In  Hawaii  some  15-year  old 
seedlings  have  large  spreading  tops  reaching  a  height  of  45  feet. 
In  form  the  trees  vary  from  slender  and  erect  to  broad  and  spread- 
ing. The  branches  differ  in  character  of  gi^owth  so  far  as  brittle- 
ness,  stiffness,  and  droojDing  habits  are  concerned,  and  the  foliage 
varies  in  color  and  size  of  leaves.  Some  varieties  yield  a  heavy 
crop  each  year  and  others  onh^  in  alternate  years.  Climatic  condi- 
tions may  account  for  some  of  this  variation. 

Roots. — The  taproot  is  rather  pronoimced  in  young  seedling 
avocados,  but  it  practically  ceases  to  extend  after  the  first  two  years 
of  growth,  and  is  a  comparatively  small  portion  of  the  root  system. 
The  secondary  roots  gi-adually  become  the  anchorage  of  the  tree  and 
the  main  channels  through  which  the  food  materials  are  conducted 
from  the  soil.  They  stretch  out  in  all  directions  through  the  upper 
layer  of  the  soil,  even  spreading  farther  horizontally  than  any  of  the 
branches  of  the  top.  The  bulk  of  the  roots  feed  between  the  eighth 
and  the  fortieth-inch  levels,  although  as  the  tree  grows  they  may 
penetrate  much  deeper  in  well-aerated  soil. 

Die-back,  which  manifests  itself  by  yellowing  of  the  shoots  and 
the  djdng  back  of  the  new  twigs  for  several  inches,  resulting  in  the 
early  death  of  the  trees,  usually  is  attributed  to  the  taproot's  hav- 
ing reached  rock  or  penetrated  into  black  volcanic  sand.  This  does 
not  appear  to  be  the  reason,  according  to  experiments  conducted 
at  the  station.  The  present  indications  are  that  the  difficulty  is 
due  to  a  combination  of  causes.  Die-back  may  be  prevented  by 
giving  the  trees  good  culture  and  by  taking  care  to  plant  them  in  a 
location  that  is  not  only  well  sheltered  from  hard  winds  but  that 
has  a  soil  rich  in  organic  matter,  and  with  good  underdrainage. 

In  experimenting  with,  the  root  system  of  the  avocado  the  station 
found  that  a  relatively  large  proportion  of  the  root  may  be  cut 
from  budded  trees  at  planting  time  without  injuring  them.  Three 
or  four  year  old  trees  may  be  successfully  moved  to  a  permanent 
place  in  the  orchard  provided  they  are  properly  handled.  Trans- 
planting must  be  done  at  the  season  of  least  rapid  growth,  and  the 
roots  should  be  covered  with  thoroughly  dampened  burlap  bags  for 
protection  from  the  sun  and  wind.  The  tops  must  be  cut  back  to 
correspond  with  the  shortening  of  the  roots  that  occurs  when  the 
trees  are  dug.     The  tree  must  be  replanted  as  soon  as  possible. 

Wood. — The  wood  of  the  avocado  is  soft,  fine  grained,  and  of  a 
color  varying  from  light  brown  to  reddish  brown.  The  heartwood 
is  slightly  mottled  with  light,  curved  spots  of  different  colors.  There 
is  little  evidence  of  annular  rings  of  growth  in  cross-section,  because 


THE   GUATEMALAN    AVOCADO   IN   HAWAII.  5 

of  the  growth  being  general  throughout  the  year.  The  bark  of  the 
tree  is  rather  thick,  rough,  and  of  light  gray  color. 

Leaves. — Tlie  leaves  of  the  Guatemalan  race  of  avocados  are  a 
rich,  dark  green  in  color,  oval,  oblong,  or  lanceolate  in  form,  and 
from  3  to  10  inches  in  length.  The  upper  surface  is  of  deep  green 
color  and  smooth,  with  depressed  veins.  The  lower  surface  is 
glaucous  or  bluish-green  colored,  with  raised  veins  which  are  slightly 
pubescent.  Leaves  of  some  varieties  are  thin  and  papery  while  those 
of  others  are  thick  and  leather\\  The  crushed  foliage  of  the  Guate- 
malan race  has  no  anise-like  odor  characteristic  of  the  Mexican  race 
of  avocados  and  the  new  growtli  is  usually  of  a  deep  bronze  red,  an 
occasional  character  of  the  new  growth  of  the  West  Indian  race. 

Flcncers, — The  flowei-s  are  perfect  and  are  borne  in  clusters  of 
panicle  arrangement,  varying  from  open  and  spreading  to  closed  and 
compact.  The  diiferent  forms  of  clusters  vary  with  the  different 
varieties  of  the  race.  They  are  small,  of  pale-green  color,  and  finely 
pubescent.  Each  flower  is  perfect,  having  both  staminate  and  pis- 
tillate organs.  The  organs  corresponding  to  calyx  and  carolla  are 
combined  into  a  perianth.  Xear  their  base  the  stamens  bear  orange- 
colored  glands  which  secrete  nectar.  The  ovary  is  one-celled  and 
contains  a  single  ovule.  The  flowers  of  this  race  are  very  similar 
to  those  of  the  West  Indian,  and  usually  appear  about  the  same  time 
or  a  little  later.  The  time  of  blooming  of  the  Guatemalan  varieties 
does  not  extend  over  such  a  long  period  as  does  the  maturing  of  the 
fruit. 

Fruit. — The  fruit  of  the  Guatemalan  avocado  is  exceedingly 
variable  in  many  of  its  characters.  In  weight  it  ranges  from  4  to  48 
ounces,  with  a  general  average  of  16  ounces.  In  form  it  is  com- 
monly oval,  but  ranges  from  spherical  to  pyriform  and  even  to 
curved-neck  pyriform.  The  rind  varies  from  a  light  gi*een  to  dark 
purple  and  may  be  smooth,  irregular,  bumpy,  rough,  or  even  warty. 
Roughness  is  often  more  pronounced  toward  the  stem  end  of  the 
fruit.  The  rind  of  different  varieties  varies  from  one-sixteenth  to 
one-fourth  inch  in  thickness,  and  is  usually  hard  and  granular.  The 
meat  is  golden  yellow.  In  some  varieties  maturity  can  not  be  deter- 
mined by  color  of  rind  or  by  pressure  with  the  thumb  and  fuigers 
on  the  firm  surface.  The  stem  will  readih'  separate  from  ripe  fruit 
upon  being  gently  pulled. 

SeM. — The  seed  is  usually  spherical  in  shape  and  is  firmly  lodged 
in  the  meat.  Were  it  not  fitted  tightly  in  the  cavity,  its  movement 
during  shipment  of  the  fruit  would  damage  the  pulp.  It  soon  loses 
its  viability,  but  when  stored  under  proper  conditions  may  remain 
viable  for  three  or  four  months.  The  seed  coats  are  thin  and  adhere 
closel}"  to  the  cotyledons,  even  after  their  removal  from  the  fruit. 

PROPAGATION. 

The  Guatemalan  avocado  may  be  propagated  by  seeds,  by  budding, 
and  by  grafting.-  Seed  propagation  is  nature's  greatest  method  of 
producing  variation,  but  it  can  not  be  relied  upon  to  reproduce  the 
variety.  Standard  varieties  of  avocados  are  maintained  onl}^  by 
asexual  methods  of  propagation,  such  as  budding,  inarching,  and 
bark  grafting.  Nearly  all  of  the  early  introductions  into  Hawaii 
came  as  selected  seeds  or  seedlings  and  have  produced  fairly  good 
fruit,  but  the  seedling  method  of  propagation  has  given  few  estab- 


6  BULLETIN   51,   HAWAII   EXPERIMENT  STATION. 

lislied  varieties.  Standard  fruits  can  be  had  only  by  asexual 
methods  of  propagating  good  varieties  in  large  numbers. 

S>eed, — This  method  of  propagation  is  of  value  principally  for 
the  production  of  rootstocks  on  which  known  varieties  may  be 
grafted.  Seedlings  may  also  be  grown  in  an  effort  to  produce  new 
varieties,  but  can  not  be  relied  upon  to  perpetuate  them.  Many 
growers  use  this  method  of  propagation  because  it  is  not  difficult 
and  they  are  satisfied  to  accept  the  results.  Seedlings  for  the  home 
garden  are  usually  propagated  in  pots  or  boxes  and  upon  attaining 
suitable  size  and  vigor  are  transplanted  to  their  permanent  place. 
This  period  may  vary  from  six  months  to  a  year.  The  seed  should 
be  selected  from  good  fruit  if  vigorous  seedling  stock  is  to  be 
produced. 

The  seeds  should  be  washed  clean  and  planted  as  soon  as  pos- 
sible after  their  removal  from  the  fruit,  being  set  in  earthen  pots, 
seed  boxes,  or  in  seed  beds  in  the  open  ground.  One-gallon  tin  con- 
tainers, such  as  are  frequently  discarded  by  pineapple  factories,  may 
be  utilized  to  good  advantage  instead  of  earthen  pots.  In  prepar- 
ing the  cans  the  tops  should  be  trimmed  and  five  or  six  large  nail 
holes  punched  in  the  bottom  for  drainage.  They  should  be  filled 
with  a  potting  soil  consisting  of  four  parts  garden  loam,  two  parts 
black  volcanic  sand,  and  one  part  thoroughly  decomposed  barnyard 
manure.  At  the  station  the  potting  soil  is  mixed  and  then  given  a 
thorough  steam  sterilization  to  destroy  insect  life,  weed  seeds,  and 
fungus  growth  that  may  be  present.  One  seed  should  be  planted 
in  each  container,  being  placed  with  the  pointed  or  upper  part 
projecting  above  the  surface.  The  plantings  should  be  set  in  the 
open  with  the  full  sun  upon  them.  Germination  will  take  place 
within  three  or  four  weeks  if  the  soil  is  kept  sufficiently  moistened, 
and  the  seedlings  will  attain  budding  and  grafting  size  in  40  to  60 
days.  At  this  time  the  plants  should  stand  1  to  2  feet  in  height  and 
have  a  stem  diameter  varying  from  one-half  to  three-fourths  of  an 
inch  at  the  customary  point  for  budding,  2  inches  above  ground. 

Care  of  seedlings. — The  seedlings  should  be  protected  fi'om  strong 
winds  and  kept  far  enough  apart  in  good  sunlight  to  avoid  making 
spindling  growth.  Newly  budded  trees  may  continue  growth  in  the 
same  containers  until  they  are  12  months  from  the  planting  of  the 
seed  without  becoming  seriously  pot-bound.  It  is  best  to  transfer 
them  to  larger  containers  if  they  begin  to  show  injury  from  root 
confinement.  Trees  propagated  in  the  above-mentioned  way  should 
be  set  in  the  orchard  in  the  cooler  months  of  the  year. 

Stock  plants. — Seedlings  of  the  avocado  itself  form  the  best  stock 
upon  which  to  grow  desirable  varieties.  It  is  thought  that  budded 
avocados  do  best  when  stock  and  cion  are  of  the  same  race,  there 
being  then  a  more  natural  union  because  of  the  similarity  of  their 
cell  structures.  Vigorous  Guatemalan  seedlings,  for  example,  should 
be  used  as  stocks  for  cions  of  desirable  varieties  of  the  same  race. 

Budding. — Shield  budding,  which  is  in  reality  a  form  of  grafting, 
is  now  the  most  commonly  used  method  of  propagating  varieties 
of  avocados.  Budding  has  long  been  practiced  in  the  propagation 
of  peaches,  plums,  etc.,  but  its  use  in  connection  with  the  avocado  is 
comparatively  new,  and  the  process  has  been  foimd  to  be  much  more 
difficult  with  the  avocado  than  with  the  other  fruits.  Experienced 
budders  often  succeed  in  developing  only  10  to  25  per  cent  of  the 


THE   GUATEMALAN   AVOCADO    IN    HAWAII.  7 

buds  into  trees.  With  such  varieties  as  the  Taft  and  Fuerte,  however, 
95  per  cent  of  the  buds  can  be  made  to  develop  into  trees.^  Success 
is  based  upon  a  number  of  factors,  inckiding  vigor  of  growth  of 
cion  and  stock,  a  sharp-edged,  thin-bladed,  clean  budding-knife, 
and  the  ability  of  the  budder  to  perform  the  operation  skillfully. 

Bud  wood. — The  buds  differ  widely  in  character  among  varieties 
of  the  same  race,  and  the  selection  of  the  proper  sort  of  bud  wood, 
especially  of  certain  varieties,  requires  keen  judgment.  For  this 
reason  the  budder  should  familiarize  himself  with  the  nature  of  the 
bud  wood  with  which  he  is  working.  (PI.  II,  fig.  1.)  Only  plumj), 
mature  buds  which  are  ready  to  break  into  growth  should  be 
selected.  Good  bud  wood  is  usually  obtained  from  new  branches 
which  have  become  fairly  mature.  This  stage  of  growth  is  reached 
in  6  to  10  weeks.  Very  little  success  is  had  with  bud  wood  from 
soft  tips.  As  soon  as  it  is  removed  from  the  tree  the  bud  wood 
should  be  wrapped  in  moistened  sphagnum  moss  and  oiled  paper. 
When  properly  packed  it  has  been  known  to  remain  in  good  condi- 
tion for  40  days.  Dampened  cloth  may  be  used  successfully  as  a 
wrapper  for  such  short  periods  as  two  or  three  days. 

The  process  of  hudding. — In  shield  budding,  a  T-shaped  or  an 
inverted  ±-shaped  incision  is  made  in  the  bark  of  the  stock,  prefer- 
ably within  about  2  inches  of  the  soil.  Unless  the  stock  is  too  dry 
to  be  budded,  the  bark  will  readily  separate  from  the  wood  when 
the  bud  is  gently  pushed  in.  The  knife  blade  should  be  turned 
slightly  forward  in  making  the  horizontal  cut  so  that  the  surface 
from  edge  to  back  is  sloping  downward.  This  forces  the  bark  away 
from  the  stock  and  leaves  a  sufficient  opening  to  receive  the  bud. 
In  cutting  the  bud,  the  thin,  sharp  blade  should  be  drawn  with  a 
single,  steady,  sliding  stroke,  keeping  the  blade  as  nearly  parallel 
with  the  bud  stick  as  possible,  making  the  cut  surface  flat  and  as 
little  rounded  as  possible  at  the  ends.  Bud  shields  of  large  bud 
sticks  are  sometimes  2  inches  long.  The  inside  of  the  shield  should 
be  cut  so  as  to  possess  a  small  portion  of  the  sapwood.  Part  of  the 
leafstalk  should  be  left  attached  below  the  bud  to  hold  the  shield 
while  it  is  being  pushed  into  place.  As  soon  as  the  bud  shield  is 
in  position  the  whole  should  be  firmly  bound  with  strips  of  moist 
raffia,  cotton  twine,  or  cotton  tape  to  prevent  the  delicate  tissues  from 
drying  out.  At  the  station  raffia  is  used  almost  entirely  for  this 
purpose. 

After  the  raffia  has  been  wound  several  times  above  and  below 
the  bud  to  cover  the  horizontal  and  the  vertical  cuts  of  the  T,  the 
ends  should  be  firmly  tied  in  a  drawing  knot  and  clipped.  Tlie 
union  should  then  be  bound  with  waxed  tape,  the  wrapping  being 
done  from  the  bottom  upward,  so  as  to  prevent  the  entrance  of 
water  to  the  bud."^  The  waxed  tape  should  be  removed  after  6  or 
8  days  and  the  raffia  12  or  14  days  later.  The  raffia,  however,  should 
not  be  left  on  long  enough  to  bind  the  native  growth.  As  soon  as 
the  waxed  tape  is  removed  the  trees  should  be  topped  back  a  few 
inches  to  force  the  new  bud  into  growth.  Along  the  stem  axillary 
buds  will  then  break  into  growth,  some  of  which  should  be  allowed 

«  Popenoe,     Manual  of  tropical  and  subtropical  fruits.     New  York.     1920. 

'A  low-melting  paraflBn  wax,  118—120°  F.,  put  on  with  a  brush  to  cover  the  bud  and 
entire  union,  has  been  found  equally  as  i^ood  as  and  of  easier  application  than  wax  tape, 
and  it  fulfills  the  same  function,  remaining  on  until  forced  off  by  natural  growth.  The 
raflfia  should  be  cut  when  there  is  evideijce  of  its  beginning  to  bind. 


8  BULLETIN   al,  HAWAII  EXPERlMENl:  STATION. 

to  grow  for  a  time  to  maintain  an  active  flow  of  the  sap.  Four  or 
five  weeks  later  the  top  should  be  cut  back  farther,  leaving  few  of 
the  lower  axillary  bud  growths.  If  the  stock  is  cut  back  too  heavily 
the  first  time,  the  eye  may  fall  from  the  bud  and  leave  a  blind 
shield.  As  soon  as  the  bud  has  made  a  growth  of  3  or  4  inches  it 
should  be  tied  upright  to  the  stem  of  the  seedling  or  be  stake  trained. 
The  remaining  stub  of  the  seedling  stock  should  be  cut  back  at  an 
angle  just  above  the  bud  and  the  cut  surface  sealed  with  grafting 
wax.  This  final  cutting  is  made  when  the  desired  bud  shoot  has 
reached  a  length  of  6  to  10  inches.     (PI.  II,  fig.  2.) 

THE  ORCHARD. 

LOCATION    OF   WINDBREAKS. 

In  the  Hawaiian  Islands,  where  there  is  likelihood  of  high  winds, 
it  is  essential  that  the  avocado  be  grown  in  a  sheltered  location. 
The  wood  of  the  tree  is  brittle,  and,  like  the  flowers  and  the  fruit, 
is  easily  broken.  Windbreaks  will  hardly  protect  an  orchard  that 
steeply  slopes  toward  the  wind,  but  protection  can  be  afforded  when 
the  slope  is  in  the  opposite  direction.  Temporary  protection  should 
always  be  given  young  trees,  whether  or  not  permanent  protection  is 
necessary.  This  may  be  supplied  in  the  form  of  burlap  which  is 
tacked  to  stakes  on  the  windward  side  of  each  tree.  Better  still  is 
the  planting  of  rows  of  pigeon  peas  between  the  rows  of  trees  across 
the  field.  This  method  has  been  thoroughl}^  tested  both  at  the  station 
and  in  the  large  Guatemalan  avocado  orchard  of  W.  D.  Baldwin 
at  Haiku.  The  pigeon  pea  improves  the  soil  in  texture  and  fer- 
tility by  its  rich  nitrogenous  vegetation.  The  panax  hedge  {Notho- 
panax  guilfoylei)  also  makes  an  excellent  windbreak,  growing 
upright  to  a  height  of  15  feet  or  more. 

Large  permanent  windbreaks,  when  necessary,  should  be  grown  on 
the  windward  side  of  the  orchard  and  should  consist  of  such  rapidly 
growing  trees  as  the  iron  wood  {Casuurina  equisetifolia)  and  eucalyp- 
tus {Eiwalyptus  rohusta).  The  mango  {Mangifera  indica)^  which 
withstands  heavy  winds,  makes  an  excellent  windbreak.  Trees  for 
shelter  purposes  should  be  started  in  a  double  row,  being  placed 
about  8  or  10  feet  apart  in  the  row,  or  even  farther  in  the  case  of 
the  mango,  with  the  windbreak  trees  alternating  in  the  row. 

ARRANGEMENT  OF  TREES. 

The  trees  should  be  so  arranged  in  the  orchard  that  the  best  results 
can  be  obtained  from  the  smallest  area.  Budded  trees  always  remain 
somewhat  dwarfed,  and  they  can  be  set  from  20  to  30  feet  apart.  A 
commercial  orchard  can  be  satisfactorily  arranged  by  setting  the 
trees  in  rows  26  by  26  feet  on  the  square,  which  will  permit  the 
growing  of  64  trees  to  the  acre.  Some  growers  recommend  that  the 
trees  be  set  30  by  30  feet,  which  will  allow  48  trees  to  the  acre.  The 
number  of  trees  per  acre  varies,  however,  according  to  the  planting 
method  used.  Any  one  of  the  several  methods  for  arrangement  of 
orchard  trees  as  described  in  popular  horticultural  works  may  be 
used  for  the  avocado  orchard.  The  most  important  of  these  are 
the  square,  triangle,  hexagonal,  and  quincunx,  the  first  being  the 
most  commonly  used. 

Several  varieties  of  avocado  should  be  intermixed  in  orchard  ar- 
rangement so  as  to  permit  of  better  pollination  at  blossoming  time. 


Bui.  51,  Hawaii    Agr.  Expt.  Station. 


Plate 


Macdonald  Avocado,  Original  Tree  (Acc.  No.  4191),  January  I,  1923. 

Brought  to  Honolulu  as  a  germinating  seed  in  1895.    Parent  of  a  number  of  good  varieties,  the 
leading  characters  of  which  have  remained  true  to  the  race  of  the  mother  parent  tree. 


Bui.  51    Hawaii   Agr.  Expt.  Station. 


PLATE     II. 


Fig.  I. — Avocado  Budwood  of  Winter-Bearing  Varieties.     I,  Fuerte; 

2,   ISHKAL;   3,  NiMLIOH;    AND   4,  BEARDSLEE. 

Varietal  characters  are  evident  in  budwood,  and  the  close  observer  who  makes  a  study  of  the 
avocado  soon  learns  to  identify  varieties  by  it. 


Fig.  2. — Budded  Avocado  Trees. 

Seedlings  are  grown  in  gallon  cans;  if  kept  growing  vigorously  they  will  be  ready  to  bud  in 
about  two  months,  after  which  it  requires  about  six  months  to  develop  them  into  budded 
trees  suitable  for  setting  in  permanent  place. 


THE  GUATEMALAN  AVOCADO  IN   HAWAII.  9 

KIND  OF  TREES  TO  PLANT. 

Only  grafted  or  budded  trees  which  have  thoroughly  united  with 
the  stock  and  have  made  thrift}^  growth  should  be  set.  Pot-bound 
trees  should  never  be  used.  Pot-grown  trees  which  have  been  given 
the  proper  care  afford  greater  opportunity  for  uniformity  than  is 
usually  the  case  when  the  seedlings  are  grown  and  grafted  in  their 
permanent  places  in  the  orchard.  Moreover,  they  can  be  removed 
from  earthern  pots  or  tin  cans  with  less  disturbance  to  their  root 
system  than  is  possible  when  trees  are  dug  from  the  nursery  rows. 

WHEN  AND  HOW  TO  PLANT. 

The  most  suitable  time  for  planting  the  trees  in  most  parts  of  the 
Hawaiian  Islands  is  from  October  to  December,  when  the  warm 
weather  has  passed  and  the  fall  rains  are  due.  If  planted  in  late 
spring  or  summer  they  have  the  most  trying  months  ahead  of  them 
for  starting  growth.  Avocados,  however,  may  be  planted  during 
any  month  with  a  fairly  reasonable  degree  of  success. 

The  holes  for  planting  should  be  at  least  3  feet  across  and  3  feet 
deep.  Surface  soil  and  sand  which  have  been  enriched  with  well- 
rotted  barnyard  manure  should  be  placed  in  the  bottom  of  the  holes 
before  the  trees  are  set.  Considerable  sand  should  be  incorporated 
with  the  soil  if  the  soil  has  a  tendency  to  be  heavy,  coral  sand  from 
the  seashore  being  preferable  for  this  purpose  on  account  of  its 
composition.  The  young  trees  should  be  inclined  slightly  toward  the 
wind  and  set  firmly  at  the  same  depth  at  which  they  stood  before 
being  transplanted,  with  the  roots  spread  in  their  natural  position. 
The  soil  innnediately  around  the  trees  should  be  several  inches 
lower  than  the  natural  surface  to  form  a  basin  which  will  hold  water 
until  the  trees  have  become  firmly  established.  After  planting,  the 
trees  should  be  liberally  supplied  with  water. 

A  stake  should  be  driven  about  1  foot  from  each  tree  on  the 
windward  side  to  act  as  a  support  during  the  first  two  years  of 
growth,  and  each  tree  should  be  firmly  tied  to  the  stake  with  a 
piece  of  burlap. 

CULTURAL  REQUIREMENTS. 

SOIL. 

In  avocado  culture  one  of  the  essential  factors  is  the  soil.  The 
trees  will  thrive  in  either  heavy  or  light  soil  provided  it  is  well 
drained.  Soils  that  are  suitable  for  citrus  growing  are  generally 
well  adapted  to  the  avocado.  The  culture  of  the  avocado  for  com- 
mercial purposes  should  not  be  attempted  in  localities  which  can 
not  be  brought  under  irrigation  or  where  there  is  little  rainfall. 
Young  trees  require  liberal  quantities  of  water  during  their  early 
years  in  order  to  maintain  vigorous  growth.  The  soil  should  con- 
tain an  abundance  of  moisture  at  the  time  the  fruit  is  setting  and 
until  several  weeks  after  fruiting  is  over.  The  avocado  tree  is  a  sub- 
tropical evergreen  and  has  no  marked  rest  period.  Soil-moisture 
must,  therefore,  be  uniformly  available  throughout  the  3^ear. 

Preparation  of  the  soil, — Preliminary  preparation  of  the  soil  of 
the  avocado  orchard  is  just  as  necessary  as  for  other  kinds  of  fruits 
or  for  field  crops.  The  land  should  be  cleared  of  all  growth,  scat- 
tered rock,  and  debris,  and  then  thoroughly  plowed  and  harrowed, 


10  BULLETIN   51,   HAWAII   EX:PERIMENT  STATION. 

before  planting.  A\liere  plowing  is  impossible,  large  holes  should  be 
dug  or  blasted  to  sufficient  depth  to  assure  good  drainage  and  ample 
feeding  area  for  the  young  roots. 

IRRIGATION. 

Water  for  irrigation  may  be  applied  in  different  ways.  The  exact 
quantity  necessary  varies  considerably  with  the  different  soils. 
Wliere  only  a  few  trees  are  to  be  watered,  the  basin  system  may  be 
used.  A  separate  basin  is  required  for  each  tree.  The  soil  should  be 
left  at  its  natural  level  for  a  space  of  several  feet  about  the  base  of 
the  tree.  Outside  of  this  area  the  basin  should  be  dug  to  a  depth  of 
6  to  8  inches,  extending  entirely  around  the  tree,  with  a  radius  of 
several  feet,  varying  according  to  the  spread  of  the  branches.  Con- 
sequently it  will  be  placed  directly  above  the  major  portion  of  the 
feeding  roots  needing  the  moisture.  The  soil  which  is  removed 
from  the  basin  should  be  formed  into  a  surrounding  ridge  to  aid 
in  holding  the  mulch  and  the  water  when  the  basin  is  filled.  The 
mulch  should  consist  of  a  coarse,  strawy  barnyard  manure.  In 
large  orchards  avocado  trees  may  be  watered  to  better  advantage 
by  the  furrow  system,  such  as  is  commonly  used  in  irrigated  com- 
mercial citrus  orchards.  The  soil  should  be  cultivated  after  each 
irrigation.  Avocado  trees  that  are  surrounded  by  grass  or  other 
volunteer  growth  and  are  watered  with  a  garden  hose  rarely  get 
enough  water  to  make  satisfactory  growth  and  are  subject  to  ir- 
regular blooming,  dropping  of  fruit,  and  occasionally  to  total  crop 
failure. 

TILLAGE. 

From  experiments  made  at  the  station  and  in  private  orchards  in 
the  Hawaiian  Islands,  as  well  as  in  Florida  and  California,  it  is 
evident  that  frequent  and  thorough  tillage  is  essential  to  excellent 
fruit  production.  Associated  with  tillage  is  intercropping  and  the 
growing  of  cover  crops. 

COVER    CROPS. 

Orchard  cover  crops  should  be  grown  during  the  wet  seasons  in 
practically  all  parts  of  Hawaii.  They  prevent  surface  washing  and 
retain  much  of  the  water  of  torrential  rains  until  it  has  had  time  to 
soak  into  the  earth  underlying  the  trees.  Another  advantage  of 
the  cover  crop  is  tl=^  gTeen  manure  which  it  furnishes,  thus  return- 
ing humus  to  the  soil.  Among  the  legumes  that  can  be  used  for  this 
purpose  are  the  pigeon  pea  {Cajanus  indicus),  cowpeas  (Vigna 
catjang)^  mungo  beans  {Phdseolus  mungo)^  soy  beans  {Glycine  his- 
pida)^  Crotalaria  {Crotalaria  juncea)  ^  white  clover  {Melilotus  alba)^ 
and  common  vetch  (Vicia  sativa).  Pigeon  peas  are  the  most  com- 
monly used  in  Hawaii.  Of  the  two  varieties  of  mungo  beans,  the 
yellow  and  the  green,  the  former  variety  is  preferred  on  account  of 
its  height  and  herbage.  Although  Crotalaria  is  as  yet  little  used  as 
a  cover  crop  in  Hawaii,  it  is  deemed  worthy  of  further  trial.  Several 
tests  of  common  vetch  at  higher  altitudes  indicate  that  it  will  be  of 
use  as  a  cover  crop  in  the  highlands.  Cowpeas  have  given  the  best 
results  of  the  legumes  as  a  cover  crop  in  the  station  orchard. 


THE   GUATEMALAN    AVOCADO   IN    HAWAII.  11 

INTERCROPPING. 

Tlie  growing  of  other  marketable  crops  between  the  rows  is  ad- 
visable, but  they  must  not  be  planted  close  enough  to  the  avocado 
trees  to  interfere  with  their  development.  "V^Hien  the  rows  are  24,  26, 
or  30  feet  apart,  papa3'a  trees  may  be  used  as  the  intercrop  at 
elevations  below  500  feet  and  a  considerable  income  derived  from 
them  before  they  become  large  enough  to  injure  the  avocados.  The 
tomato  is  an  excellent  crop  for  interplanting,  and  the  fruit  usually 
brings  a  good  price  in  the  local  markets.  Such  other  crops  as  the 
sweet  potato,  string  bean,  pepper,  squash,  peanut,  and  alfalfa  may 
also  be  grown  successfully.  At  elevations  of  1,000  feet  or  more, 
roselle  {Hibiscus  sahdariffa),  poha  berries  {Physalis  peruviana)^ 
chayote  (Sechiitm  edide),  and  water  lemon  (  Passifiora  laurifolia) 
can  be  satisfactorily  used  as  intercrops.  Sweet  corn  offers  a  possi- 
bility as  an  intercrop  and  Avould  find  an  almost  unlimited  market 
localh'. 

When  it  is  desired  to  grow  two  kinds  of  permanent  crops,  the 
avocado  tree  rows  may  be  interspaced  with  rows  of  coffee  trees. 
Guatemalan  avocados  and  coffee  can  be  grown  in  combination  very 
well,  since  the  requirements  of  the  two  crops  are  very  similar  and 
each  bears  at  a  different  season. 

PRUNING. 

Well-grown  Guatemalan  avocado  trees  require  little  or  no  pruning 
other  than  the  pinching  out  of  tender  buds-  which  would  become 
undesirable  branches.  The  kind  and  amount  of  pruning  varies  with 
the  different  varieties.  In  most  cases  it  is  desirable  to  keep  the  tops 
low,  with  the  lower  branches  shading  the  ground  as  much  as  possible. 
Such  trees  are  less  subject  to  the  force  of  the  wind  than  are  high- 
headed  trees  and  can  easil}^  be  propped  when  necessary,  while  their 
lower  branches  help  to  conserve  moisture  and  bring  the  fruit  within 
easy  reach  of  the  gatherer.  AATien  these  trees  grow  older,  the  lower 
branches  should  be  gradually  trimmed  back  and  finally  removed 
to  make  room  for  the  upper  larger  ones  which  bend  down.  The  aim 
should  be  to  secure  a  strong  symmetrical  tree  having  well-spaced 
branches  which  will  readily  sustain  heavy  crops  of  fruit.  A  con- 
siderable portion  of  the  top  should  be  removed  from  trees  that  have 
become  one-sided  from  exposure  to  continuous  wind.  Dead  twigs  in 
the  fruit -producing  area  and  dead  branches  in  the  interior  of  the 
tree  should  be  cut  out  as  also  deadwood  or  branches  which  have 
been  affected  by  wood-boring  insects  of  the  genus  Xyleborus. 

Avocado  trees  may  be  pruned  to  some  extent  at  almost  any  time 
of  the  year  if  it  is  necessary  to  restrain  the  growth  of  the  branches. 
Undoubtedly  the  best  and  safest  time  to  prune  is  when  there 
seems  to  be  least  activity  of  growth.  Heavy  pruning  is  likely  to 
force  vegetative  growth  rather  than  fruit  wood. 

Sharp  pruning  shears  should  be  used  for  the  removal  of  small 
branches  and  the  pruning  saw  for  large  limbs.  All  wounds  that  are 
three-eighths  of  an  inch  or  larger  in  diameter  should  be  smoothed 
off'  with  a  sharp  pruning  knife  and  painted  to  prevent  die-back  or 
the  entrance  of  insects.  Asphaltum  paint  has  been  satisfactorily 
used  where  considerable  pruning  has  been  done.  Preparatory  to 
being  used  the  asphaltuxn  should  be  thoroughly  melted  and  then 


12  BULLETIN   51,   HAWAII  EXPERIMENT   STATION. 

diluted  with  gasoline  (after  removal  from  the  fire)  until  it  forms 
a  mixture  that  has  on  cooling  the  consistency  of  thick  paint  which 
liardens  on  drying. 

FERTILIZERS. 

Very  little  systematic  attention  has  as  yet  been  given  the  subject 
of  fertilizing  the  avocado.  No  serious  problems  regarding  fertilizer 
requirements  have  arisen  during  the  short  time  the  fruit  has  been 
under  commercial  cultivation.  From  experiments  conducted  at  the 
station  it  has  been  found  that  the  avocado  tree  responds  readily  to 
fertilizer  in  vegetative  growth  as  well  as  in  texture  and  flavor  of 
fruit.  Avocado  trees  of  bearing  age  which  were  in  serious  condition 
have  been  restored  to  vigor  and  fruitfulness  Avhen  given  applications 
of  barnyard  manure  either  as  a  mulch  in  irrigation  basins  under  the 
trees  or  when  worked  into  the  loosened  surface  soil  above  the  feeding 
roots.  In  most  of  the  experiments,  however,  water  in  abundance  has 
doubtless  been  an  important  restoring  factor.  It  is  advisable  to  use 
caution  in  fertilizing  avocado  trees,  particularly  with  highly  nitro- 
genous fertilizers  or  such  as  will  leave  too  much  organic  matter  in 
the  soil.  Like  heavy  pruning,  heavy  fertilizing  is  likely  to  force 
vegetative  growth  at  the  expense  of  fruit  wood  and  to  result  in  a 
greatly  diminished  production  of  fruit  for  several  years. 

THE  CROP. 

TIME    OF    MATURITY. 

The  age  at  which  budded  Guatemalan  avocado  trees  come  into  bear- 
ing depends  upon  the  variety.  Some  varieties  bear  fruit  in  their 
third  year,  and  practically  all  those  worthy  of  cultivation  should 
produce  at  least  a  few  fruits  in  their  fourth  year.  The  season  of 
maturity  of  the  fruit  of  a  variety  may  vary  with  climatic  and  other 
conditions  under  w^hich  it  is  grown,  such  as  latitude,  altitude,  humid- 
ity, and  the  like.  For  example,  the  Tumin  variety  of  the  Popenoc 
collection  matures  its  crop  in  February  when  grown  at  an  elevation 
of  about  1,000  feet  at  the  Tantalus  substation,  Oahu,  and  from  May 
to  June  when  grown  5,100  feet  above  sea  level  in  its  native  place 
of  Antigua,  Guatemala.  With  the  combination  of  varieties  from 
different  environments,  mature  fruits  may  be  obtained  in  Hawaii 
practically  throughout  the  year. 

HARVESTING. 

Avocados  picked  when  immature  and  allowed  to  ripen  sometime 
become  edible,  but  are  likely  to  be  watery  and  insipid.  The  shipment 
of  such  fruit  should  not  be  encouraged,  as  it  will  soon  injure  a  grow- 
ing trade.  Fruits  which  are  purple  when  ripe  do  not  usually  develop 
their  color  until  they  reach  the  last  stage  of  maturity.  This  fact 
may  serve  as  a  guide  in  determining  the  time  of  picking.  It  is  rather 
difficult  to  determine  the  time  of  maturity  of  varieties  which  retain 
their  green  color.  Close  observation  usually  shows  that  such  fruit 
undergoes  a  slight  change  in  shade  of  skin  and  stem  which  indicates 
the  proper  degree  of  maturity.  The  grower  will  soon  become  famil- 
iar with  the  peculiarities  of  each  variety  and  learn  to  make  the 
proper  selection  at  harvest  time.  If  not  picked  wlien  mature,  the 
fruit  of  some  varieties  will  remain  on  the  tree  for  weeks  and  even 
for  months  after  the  normal  season  for  harvesting  has  passed.    In 


THE   GUATEMALAN   AVOCADO   IN    HAWAII.  13 

other  cases  the  seed  sprouts  in  the  cavity  of  fruits  which  are  left  too 
long  on  the  tree. 

Avocados  should  be  cut  from  the  tree  and  not  pulled  or  broken  off. 
Orange  clippers  are  excellent  for  this  purpose.  The  stem  should  be 
cut  just  above  the  point  of  attachment  where  it  is  enlarged.  A  step- 
ladder  can  be  used  in  picking  fruit  from  the  higher  branches  and 
properly  constructed  long-handled  pickers,  for  plucking  the  fruit 
from  the  top  of  the  trees.  In  Florida,  where  the  avocado  is  grown 
for  shipment  to  distant  markets,  regular  fruit  pickers,  having  a  bag 
attachment  at  the  end  of  the  pole,  are  used  in  harvesting  avocados. 
Some  growers  collect  the  fruit  in  baskets. 

PACKING  AND  MARKETING. 

The  present  method  of  picking,  packing,  and  marketing  avocados 
in  Hawaii  is  unsatisf actoiy  even  for  local  trade.  Too  often  the  fruit 
shows  the  results  of  rough  handling.  Fungus  spores  soon  get  a 
foothold  if  the  stem  is  pulled  out,  and  there  is  likely  to  be  great  an- 
noyance in  handling  fruit  which  has  been  broken  off  with  the  stem 
adhering.  The  fruit  should  be  carefully  handled  if  the  industry  is  to 
develop  to  desirable  proportions. 

In  Florida  the  standard  package  for  shipment  of  avocados  is  a 
well-made  crate,  the  dimensions  of  v/hich  are  12  by  12  by  24  inches. 
Each  crate  holds  from  18  to  36  fruits,  depending  upon  their  size.  The 
crates  are  similar  in  shape  to  the  standard  California  orange  box 
and  have  a  partition  in  the  center.  Fine  excelsior  is  placed  above 
and  below  each  layer  of  fruit  and  between  it  and  the  box  to  prevent 
any  possibility  of  shaking  and  to  permit  a  slight  circulation  of  air 
in  the  box.  The  Guatemalan  varieties  should  be  packed  firmly  in 
the  crate,  but  not  as  tight  as  oranges  are  packed.  Fruit  so  packed 
can  be  shipped  short  distances  without  refrigeration  and  long  dis- 
tances with  refrigeration. 

YIELDS. 

Most  local  bearing  trees  of  the  Guatemalan  avocado  are  seedlings. 
Budded  trees  have  not  as  yet  been  in  cultivation  long  enough  to  per- 
mit of  their  maximum  production  being  known.  In  1900  the  original 
Macdonald  avocado  tree  began  to  attract  attention  as  a  prolific 
yielder  of  good  fruit  in  the  winter  months.  Although  the  tree  has 
been  under  rather  close  observation  since  that  time,  few  definite 
records  are  available  showing  the  nimiber  of  fruits  produced  in  a 
season.  It  is  estimated  that  from  300  to  400  fruits  have  been  pro- 
duced in  some  seasons  and  occasionally  few  fruits  in  other  seasons. 
A  light  crop  is  usually  followed  by  a  heavy  one.  Tlie  habit  in  fruit 
trees  of  producing  heavy  and  light  crops  alternately  has  been  over- 
come to  considerable  extent  by  good  cultural  methods.  The  original 
Macdonald  tree  produced  a  large  crop  in  1921,  followed  by  a  light 
crop  in  1922.  In  January,  1923,  it  matured  a  crop  of  300  fruits, 
which  is  a  fairly  large  yield  in  view  of  the  size  of  the  tree  and  the 
little  attention  it  has  received. 

The  Kalua^  avocado  tree,  located  in  Wailuku,  Maui,  at  an  eleva- 
tion of  about  280  feet  above  sea  level  is  reported  by  its  OAvner,  Judge 
Kalua,  as  being  prolific.  A  study  made  of  this  tree  during  the  past 
two  years  shows  that  it  is  very  productive  under  adverse  conditions. 

^  Sometimes  misspelled  "  Kailua." 


14  BULLETIN    51^   HAWAII   EXPERIMENT  STATION. 

A  17-year-old  tree  of  the  Bon  variety  produced  a  crop  of  about  600 
fruits  in  1922.  These  were  sold  on  the  tree  for  $100  and  retailed  on 
the  local  markets  for  60  cents  apiece. 

The  estimated  production  of  fruit  of  a  14-year-old  tree  of  the 
variety  Wilder  for  the  past  few  years  has  been  between  250  and  300 
fruits.  Seven  to  ten  year  old  trees  of  the  Beardslee  variety  have 
made  some  very  favorable  records  of  several  hundred  fruits  per  tree 
per  season.  Both  Wilder  and  Beardslee  are  inclined  to  produce 
heavy  and  light  crops  alternately  unless  carefully  regulated. 

CONTROL  OF  INSECT  ENEMIES. 

Insect  enemies  of  the  Guatemalan  avocado  are  not  numerous  in 
Hawaii. 

MEALYBUGS. 

The  avocado  mealybug  {Pseudococcus  nipa)  is  the  most  serious 
of  the  insect  pests.  Fullaway,^  in  writing  of  their  control  says  the 
symbiotic  relationship  between  ants  and  mealybugs  is  largely  re- 
sponsible for  their  dissemination  and  presents  an  added  difficulty  in 
attempting  to  cope  with  them.  Trees  infested  with  mealybugs  lose 
most  of  their  foliage  and  show  a  loss  of  vigor;  young  trees  are  killed. 

Control. — Kerosene  oil-emulsion  sprays  are  the  most  effective 
means  of  control  for  avocado  mealybugs.  The  following  is  the  form- 
ula for  making  the  emulsion : 

Common  laundry  soap pound ^ 

Kerosene  (coal  oil) gallons 2 

Water do 1 

The  soap  should  be  dissolved  in  water  while  it  is  boiling  over  a 
fire.  The  solution  should  then  be  removed  to  a  safe  distance  from 
the  fire  and  the  kerosene  added  to  it.  The  mixture  should  be  vio- 
lently agitated  until  it  has  a  creamy  consistency,  thickens  on  cooling, 
and  shows  no  trace  of  free  oil  on  the  surface.  A  perfect  emulsion  is 
best  procured  by  charging  and  discharging  the  spray  pump  in  the 
mixture  for  10  minutes,  the  direct -discharge  nozzle  having  an  open- 
ing which  will  throw  a  strong  stream.  This  is  a  stock  solution,  and 
when  properly  made  and  protected  from  air  will  keep  for  several 
weeks.  Wien  used,  the  stock  solution  should  be  diluted  with  water 
(1  part  of  the  solution  to  15  parts  of  water).  The  emulsion  should 
be  E^pplied  to  the  infested  part  of  the  tree  with  the  spray  pump. 

Another  oil-emulsion  spray  which  is  often  used  for  mealybugs 
in  much  the  same  way  as  the  kerosene-emulsion  spray  is  San-U-Zay 
oil,  which  has  the  following  formula : 

San-U-Zay   oil part  __     1 

Water parts__  35 

The  mixture  should  be  thoroughly  agitated  by  means  of  a  wooden 
paddle  before  being  applied  as  a  spray.  The  oil  separates  when  the 
emulsion  is  allowed  to  stand  for  several  days,  but  the  emulsified 
form  is  restored  when  a  little  sal  soda  is  stirred  in. 

WOOD-BORING  BEETLES   (Xyleborus  immaturus). 

Wood-boring  beetles  often  enter  the  trunk  or  larger  branches 
where  the  wood  is  exposed  following  injury,  and  in  many  cases  work 
into  the  live  wood  beneath  the  bark.     Unless  prevented,  they  will 

»  Hawaii  Sta.  Bui.  25,  The  avocado  in  Hawaii,  p.  22.     1911. 


THE   GUATEMALAN    AVOCADO    IN    HAWAII.  15 

soon  kill  the  tree.  Their  presence  is  easily  detected  by  the  w^hite, 
frost-like  deposit  which  the  exuding  sap  leaves  on  the  outer  bark 
after  the  moisture  has  evaporated  from  it. 

Control. — Carbolic-acid  emulsion  has  recently  been  used  with 
success  as  a  control  measure  at  the  station  and  also  in  private 
orchards.     The  emulsion  is  made  as  follows : 

Crude   carbolic  acid gallon.-  1 

Common  laundry  soap do 8 

Water   (hot) do 8 

The  soap  should  be  cut  into  thin  shavings  and  dissolved  in  boiling 
water,  after  which  the  carbolic  acid  should  be  added  to  it.  The 
whole  should  then  be  allowed  to  boil  for  a  considerable  time.  Diluted 
with  water  (1  part  solution  to  20  parts  water),  this  solution  is  used 
both  as  a  wash  and  as  a  spray  for  the  trees  attacked. 

Avocado  branches  showing  the  work  of  boi^rs  should  be  removed 
and  burned.  If  the  beetles  have  not  progressed  too  far  in  their  work 
of  destruction,  they  may  be  dug  from  the  trunk  before  the  solution  is 
applied.    All  scars  should  be  covered  with  asphaltum  paint. 

GREEN   CATERPILLAR. 

The  green  caterpillar  of  the  tortricid  moth  {Amorbia  emigratella) 
occasionally  injures  the  foliage  of  avocado  trees,  particularly  young 
trees.  The  caterpillar  is  a  form  of  leaf  folder  which  draws  the 
edges  of  the  leaf  together  and  then  retreats  temporarily  into  the 
shelter  thus  afforded.  At  feeding  time  it  emerges  and  eats  the 
tissues  of  the  leaf.  The  adult  moth  has  a  wing  expanse  of  about  an 
inch  and  is  of  brown  color. 

Control. — The  green  caterpillar  may  be  controlled  by  the  use  of 
arsenical  spray. 

Arsenate   of   lead    (paste  form) ounce__  1 

Water gallon 1 

Or 

Arsenate  of  lead  (powdered  form) ounce I 

Water gallon 1 

The  spray  should  be  applied  as  soon  as  there  is  evidence  of  injury 
from  the  green  caterpillar  and  should  be  repeated  as  often  as  neces- 
sary. Arsenate  of  lead  is  much  less  likely  to  injure  the  foliage  than 
is  Paris  green  and  it  is  more  effective. 

COMPOSITION  OF  THE  FRUIT. 

Although  anah'ses  do  not  indicate  just  what  varieties  of  avocados 
it  is  best  to  grow,  they  do  show  in  a  general  way  the  nutritive  value 
of  the  fruit  and  thus  help  to  determine  its  place  in  the  dietary.  A 
fruit  containing  a  high  percentage  of  one  or  more  essential  constitu- 
ents may  be  undesirable  because  of  peculiar  flavor  caused  by  some 
other  constituent.  In  the  Guatemalan  avocado  the  proportions  of 
the  constituents  change  in  each  variet}^  according  to  the  degree  of 
maturity  of  the  fruits  and  vary  in  different  years  and  in  different 
localities. 

Unfortunately  very  little  data  are  available  regarding  analyses 
of  the  Guatemalan  avocado.  Analj^ses  of  a  few  locally  grown 
varieties  show  no  striking  differences  in  composition  between  them 
and  those  tested  in  California.  The  following  table  affords  a  com- 
parison of  the  composition  of  the  edible  portion  of  Hawaii-grown 
with  that  of  California-grown  Guatemalan  avocados. 


16 


BULLETIN    51,    HAWAII    EXPERIMENT  STATION. 


Comparison  of  composition  of  Guatemalan  avocados  grown  in  Hawaii  aaid  in 

California. 


Variety. 


Water. 


Protein. 

Fat. 

Per  cent. 

Per  cent. 

1.22 

26.73 

1.60 

18.72 

.82 

22.62 

1.10 

19.50 

2.53 

14.85 

1.31 

15.87 

2.88 

16.35 

2.15 

15.73 

2.48 

16.31 

1.27 

3.85 

1.25 

29.14 

Carbohydrates. 


Crude 
fiber. 


Nitrogen- 
free  ex- 
tract. 


Ash. 


Hawaii  experiment  station:  Per  cent. 

Nutmeg i  63. 58 

Bon 73. 13 

Towse I  70. 38 

Cockett 73.  84 

Ace.  No.  4922 '  75. 82 

Wilder  i 76. 81 

University  of  California: 

Blakeman i  76. 02 

Sharpless '  76. 73 

Lyon I  76. 78 

Solano ,  90. 62 

Fuerte ■  60. 86 


Percent. 
2.04 
1.65 
1.36 
1.51 
1.62 
5. 

3. 
3. 
4. 
3. 

7. 


Per  cent. 
4.72 
3.56 
3.43 

2.78 
3.84 
15 

77 


Per  cent. 
1.71 
1.24 
1.39 
1.27 
1.34 


1.70 

1.05 
.62 
1.35 


1  The  analysis  of  Wilder's  Guatemalan  No.  1  was  made  by  the  University  of  California  and  furnished 
through  the  courtesy  of  G.  P.  Wilder,  Honolulu. 

Fat. — The  analyses  show  that  the  avocado  contains  a  very  high 
percentage  of  fat  and  constitutes  an  important  source  of  vegetable 
oil.  The  Xutmeg,  a  variety  of  Hawaiian  origin,  analyzed  26.73  per 
cent  crude  fat.  In  one  analysis  the  variet}^  Fuerte  gave  a  fat  content 
in  California  of  30.72  per  cent.  The  only  fruit  comparable  with  the 
avocado  in  fat  content  is  the  olive,  and  a  number  of  analyses  indicate 
that  the  avocado  ranks  higher  in  fat  content  than  does  the  average 
or  commonly  used  olive.  The  digestibility  of  the  avocado  has  been 
found  to  be  equal  to  that  of  butterfat  and  not  below  that  of  beef  fat. 

Protein. — The  protein  content  of  the  Guatemalan  avocado  averages 
about  1.5  per  cent,  which  is  somewhat  above  that  of  most  other  fruits. 

Ask. — Five  varieties  of  locally  grown  Guatemalan  avocados  which 
Nvere  analyzed  by  the  Hawaii  station  showed  an  average  ash  content 
of  1.39  per  cent.  This  is  much  higher  than  is  found  in  other  fresh 
fruits,  and  is  somewhat  higher  than  the  ash  content  of  a  much  larger 
number  of  varieties  of  several  races  of  avocados  which  were  analyzed 
in  California.  Tlie  analyses  as  made  in  California  give  the  average 
percentage  of  pure  ash  of  the  edible  portion  of  the  avocado  as  1.14, 
which  contrasts  with  the  averages  of  other  California  fruits,  as  fol- 
lows: Grapes,  0.5  per  cent;  pi-unes,  0.565:  plums.  0.524:  apricots, 
0.484;  nectarines.  0.49:  figs,  0.6;  lemons,  0.535:  and  oranges,  0.5. 

The  various  mineral  substances  are  contained  in  the  ash  of  a  fruit, 
and  in  the  study  of  dietetics  it  is  important  to  know  what  kind  of 
mineral  a  fruit  may  contain  when  used  as  a  food.  There  should  be 
proper  balance  between  base-forming  and  acid- forming  elements  in 
the  dietary.  Xuts,  for  example,  belong  to  the  foods  furnishing  the 
acid-forming  elements  in  excess  and  for  this  reason  should  be  used 
in  combination  with  certain  fruits.  Investigations  show  that  the 
avocado  belongs  to  the  class  of  foods  yielding  an  excess  of  base-form- 
ing elements,  while  in  the  ash  of  cereals,  nuts,  meats,  eggs,  and  the 
like  phosphoric  acid  greatly  predominates.  This  element  is  found 
only  in  relatively  small  amounts  in  avocados  and  most  other  fruits. 
In  this  connection  it  is  well  to  note  that  the  avocado  has  a  low  lime, 
as  well  as  phosphoric  acid,  content,  and  therefore  has  no  great  amount 
of  bone  building  material. 


Bui.  51,  Hawaii    Agr.  Expt.  Station. 


Plate  III, 


\   ■ 

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Bui.  51,  Hawaii    Agr.  Expt.  Station. 


PLATE    IV. 


Fig.  I. — Wilder  (Acc.  No.  4540). 

Has  gained  considerable  reputation  for  its  fine  quality.  Original  tree  was  grown  by  Gerrit  P. 
Wilder.  The  tree  is  large,  vigorous,  and  prolific.  The  fruit  is  unlike  that  of  the  mother 
parent,  the  Macdonald,  in  size,  smoothness  of  surface,  and  color  which  remains  green  at  full 
maturity. 


Fig.  2. — Beardslee  (Ables,  Acc.  No.  4075). 

One  of  the  leading  varieties  propagated  by  budding  in  Hawaii.  It  is  of  excellent  quality. 
This  variety  should  be  interplanted  among  several  other  varieties  blossoming  at  the  same 
time  to  give  a  more  perfect  pollination  and  eventually  a  more  regular  fruit  production  than 
is  the  case  otherwise. 


Bui.  51,  Hawaii   Agr.  Expt.  Station. 


Plate  v. 


Fig.  I.— The  Kalua  (Acc.  No.  34I3\ 

A  favorite  on  account  of  its  long  fruiting  period,  November  to  March.    The  original  tree  was 
one  of  the  three  brought  to  Hawaii  by  Admiral  Beardslee  in  1895. 


^  ^m               -'^'                ^ 

^^^*  ^'  -•                          ^^^mk^"^^^^^ 

(@)    ^'^ 

tfpir^l'-  ■  ■'       -    '■■■  ■ 

The     Malpy  Avocado 

Fig.  2. — The  Haley  (Acc.  No.  4821). 

Comes  into  bearing  at  an  early  age,  and  the  fruit  has  very  desirable  qualities. 


Bui.  51,  Hawaii    Agr.  Expt.  Station. 


Plate  VI. 


pa 


THE   GUATEMALAN    AVOCADO    IN    HAWAII.  17 

Carbohydrates. — The  total  carbohydrate,  including  crude  fiber 
and  nitrogen-free  extract,  is  not  high  in  the  avocado  as  compared 
with  that  of  many  other  ripe  fresh  fruits.  The  crude  fiber  or  solid 
matter  remains  far  greater  than  is  noted  for  most  other  fruits.  The 
avocado  contains  a  small  amount  of  sugar,  of  which  only  about  50 
per  cent  is  saccharose.  The  studies  of  the  avocado  made  by  Prinsen- 
Geerlings  give  the  total  sugars  as  1.72  per  cent  in  the  proportion  of 
0.4  per  cent  glucose,  0.46  per  cent  fructose,  and  0.86  per  cent  saccha- 
rose. 

USES. 

The  avocado  is  used  in  Hawaii  in  many  ways.  It  is  served  on  the 
half  shell,  for  which  purpose  it  is  well  adapted,  the  flesh  being 
scooped  out  with  a  spoon.  The  fruit  is  also  cut  in  halves  or  quarters, 
depending  upon  its  size,  and  served  with  seasoning  or  dressing,  and 
it  is  served  with  or  immediately  following  the  soup  course.  The 
avocado  is  also  commonly  eaten  as  a  salad,  being  sliced  or  cut  into 
cubes  and  served  with  salt  and  lime  juice  or  with  salt  and  vinegar 
to  bring  out  the  flavor.  Mayonnaise,  which  contains  about  95  per 
cent  oil,  should  not  be  used  with  avocados,  because  the  latter  has  an 
oil  content  of  about  20  per  cent.  The  delicate  flavor  of  the  fruit 
is  lost  when  mayonnaise  is  used,  and  especially  if  it  is  served  with 
catsup,  cocktail,  celery,  nuts,  or  onions,  regardless  of  the  fact  that 
various  recipes  recommend  their  use  with  the  avocado. 

In  its  native  land  the  avocado  is  greatly  liked  by  the  Indians,  who 
break  the  fruit  in  half,  season  the  pulp  with  salt,  and  scoop  it  out 
with  tortillas  (corn  cakes). 

In  summer,  when  there  is  an  overproduction  of  the  West  Indian 
variety,  the  avocado  is  successfully  fed  to  hogs  and  laying  hens  in 
parts  of  Hawaii. 

EXPERIMENTS  IN  PROGRESS. 

The  objects  of  the  Guatemalan  avocado  investigation  begun  by  the 
station  in  1918  are  to  introduce  new  varieties  of  the  hard-shelled  type, 
determine  the  best  conditions  of  their  culture  in  Hawaii,  test  a  num- 
ber with  the  hope  of  being  able  to  select  a  group  maturing  high- 
grade  fruit  throughout  the  year,  and  encourage  the  culture  of  budded 
varieties  so  that  there  will  be  established  a  standard  fruit  for  com- 
mercial purposes  as  well  as  for  the  home  orchard. 

The  plantings  have  been  made  in  a  wooded  valley  on  the  slopes 
of  Tantalus,  where  the  soil  is  deep  and  rich,  being  a  well-drained 
decomposed  black  volcanic  sand.  The  elevation  at  this  place  is 
about  1,000  feet,  the  climate  is  cool,  and  the  rainfall  suitable 
for  growing  the  avocado.  In  fact,  the  conditions  are  intermediate 
in  relation  to  those  throughout  the  Territory  where  the  Guatemalan 
avocado  is  largely  grown.  The  first  trees  were  set  out  in  May,  1919. 
Of  22  varieties  received  by  mail  from  the  United  States  Department 
of  Agriculture,  all  but  four  survived  the  long  journey  and  are  now 
making  fairly  good  growth.  The  varieties  under  trial  and  their 
identification  numbers  are  as  follows  :^^ 

10  For  a  detailed  description  of  these  varieties  the  reader  is  referred  to  U.  S.  Dept. 
Agr.  Bui.  743,  The  avocado  in  Guatemala^  pp.  43-69,  copies  of  which  may  be  had  from  the 
Superintendent  of  Documents,  Washington,  D.  C,  at  30  cents  each. 

84456°— 24 2 


18 


BULLETIN    51^    HAWAII   EXPERIMENT   STATION. 


Guatemalan    avocados    of    the 

Popenoe   collection 
substation. 

growing    at 

the    Tantalus 

Varieties. 

S.  P.L 

niimber. 

Varieties. 

S.P.I, 
number. 

AkbaL....' 

45505 
44626 
43560 
44681 
44439 
44785 
43935 
43932 
45,563 

Manik 

45560 

Benik 

Kanola 

Tertoh                                 

44856 

Kayab 

'  Ishdm 

45562 
43602 

Nabal 

Ishkal 

Pankay 

43934 

Chisoy 

Mavapan 

44680 

Coban 

44625 

Kanan 

Tnmin 

44627 

1 

Pankay,  Nabal,  Ishkal,  Panchoy,  and  Tuinin  blossomed  during 
March,  1922.  Tumin  was  the  only  variety  to  set  fruit,  seven  of 
which  reached  maturity  in  February  and  March,  1923.  This  variety 
was  the  first  of  the  Popenoe  collection  to  fruit  at  the  experiment 
station  and  appears  to  have  qualities  of  considerable  promise.  The 
orchard  has  been  kept  well  cultivated,  and  the  trees  have  been 
sprayed  on  several  occasions  to  control  the  avocado  mealybug  and 
the  leaf  folder. 

In  connection  with  the  above-mentioned  experiments,  a  suitable 
technique  for  the  pollination  of  locally  grown  varieties  is  being 
determined  in  the  hope  of  uniting  desirable  characters  of  different 
varieties. 

In  another  section  of  the  Tantalus  substation  orchard  50  seedlings 
of  the  Macdonalcl  avocado  are  being  gTown  to  permit  a  study  of 
the  natural  variation  that  may  occur.  The  remarkable  variation  that 
has  already  taken  place  with  the  original  Macdonald  avocado  tree  in 
the  production  of  the  varieties  Wilder,  Beardslee,  Xutmeg,  and  pos- 
sibly others,  indicates  that  this  variety  is  particularly  subject  to 
variation  in  desirable  directions.  In  this  connection  it  may  be  noted 
that  the  Macdonald  avocado  tree  is  located  in  a  large  backyard 
where  no  other  trees  of  Guatemalan  type  grow,  and  it  was  the  only 
one  of  its  kind  on  the  island  of  Oahu  during  the  years  when  seeds 
grew  producing  the  above-mentioned  A'arieties.  There  were  in  the 
yard,  during  that  time,  from  1  to  7  avocado  trees  of  West  Indian 
type,  but  these  were  located  from  50  to  300  feet  away  on  at  least 
three  sides  of  the  Macdonald  tree.  There  were  also  West  Indian  avo- 
cados in  other  parts  of  the  locality,  some  of  which  were  in  blossom 
at  the  same  time  the  Macdonald  tree  was  in  bloom.  Possibly  the 
Macdonald  was  pollinated  by  these  trees,  which  fact  would  account 
for  the  variations  of  form,  color,  and  other  characters  in  the  progeny. 
The  characters  of  the  mother  i^arent,  the  Macdonald  avocado  tree, 
greatly  predominate,  however.  If  the  Guatemalan  tree  was  entirely 
self-pollinated,  then  its  seedling  offspring  have  varied  remarkably 
in  desirable  directions.     This  problem  is  being  investigated. 

The  Wilder  hybrids,  consisting  of  the  varieties  Lahi,  Calabash, 
Ilialu,  Lehua,  and  Kinau,"  are  a  very  interesting  and  valuable 
group.  All  the  crosses  were  made  by  Gerrit  P.  Wilder  in  the  spring 
of  1914.  The  Guatemalan  variety  Wilder  was  crossed  with  West 
Indian  pollen  and  the  seedling  trees  resulting  were  set  in  the  late 

11  These  Hawaiian  names  have  the  following  meanings  :  Lahi,  thin  ;  Calabash,  shaped 
like  a  calabash  ;  Ilialu,  rough  rind  ;  Lehua,  red  ;  and  Kinau,  name  of  a  princess. 


THE   GUATEMALAN   AVOCADO    IX    HAWAII. 


19 


fall  of  that  year  at  "  Esbank/'  the  old  Wilder  home,  60  Judd  Street, 
Honolulu.  The  five  trees  fruited  in  their  fifth  and  sixth  years,  pro- 
ducing fruit  of  desirable  quality,  indicating  their  worth  for  propa- 
gating asexually  as  varieties.  The  trees  vary  somewhat  in  appear- 
ance, mainly  in  shape  of  tops.  The  foliage  of  all  has  the  apparent 
characters  of  the  Guatemalan.  The  fruit  of  each  tree  differs  from 
that  of  the  others,  mainly  in  shape  and  character  of  rind,  some  being 
warty  and  others  smooth.  All  the  varieties  mature  their  fruit  either 
in  late  fall  or  early  winter.  The  group  is  particularly  interesting 
to  plant  breeders  and  shows  the  great  possibilities  for  creating  new 
and  valuable  varieties  of  avocados. 

The  following  brief  outline  shows  the  relation  of  varieties  as  to 
parent  trees  and  their  progeny : 

fLahi  (No.  4926). 

Calabash  (No.  4674). 
WUder  (No.  4540;  hybrids) Uhalu  (No.  4696). 

Lehua  (No.  4695). 


Macdonald 
4191)^2  __ 


(Ace.      No. 


Nutmeg  (No.  4076). 
Beardslee  (No.  4075). 
Haley  (No.  4821). 
(No.  4922). 


iKinau  (No.  4675). 


Holt  (No.  4819). 
Towse  (No.  4818). 
(No.  4924). 


Bon  (No.  4820). 

Mclnerny,  and  several  others. 

Kalua  (Ace.  No.  3413)  .-{^^'^  ^^(No.^lS15) : jCockett  (No.  4817). 

DESCRIPTION  OF  VARIETIES. 

THE  MACDONALD  AVOCADO. 

The  Macdonald  avocado  (No.  4191)  (PI.  Ill,  fig.  1)  began  to 
attract  attention  probably  as  early  as  1900.  At  first  it  was  slow  to 
meet  with  favor  probably  because  of  its  warty  rind  and  its  size, 
which  was  small  when  compared  with  that  of  the  West  Indian 
avocado.  '\"\Tien  interested  persons  began  growing  its  seedlings, 
however,  they  were  soon  attracted  by  the  wide  variation  in  the  pro- 
geny and  by  the  exceptionally  fine  fruit.  Macdonald  is  an  excellent 
shipper  and  has  fine  keeping  qualities,  the  fruit  remaining  in  a  per- 
fect state  of  preservation  when  kept  at  ordinary  room  temperatures 
for  two  or  three  weeks  after  harvesting. 

Description  of  tree. — Upright  and  spreading,  reaching  a  height 
of  40  feet  and  a  spread  of  top  of  30  feet  in  30  years.  The  foliage  is 
generally  scant,  dark  green  in  color,  and  the  leaves  average  small 
for  a  Guatemalan.  Each  fruit  hangs  separately  on  a  long  stem,  often 
12  inches  in  length.  The  tree  often  carries  fruit  over  through  the 
blossom  period  of  the  following  season. 

Fruit. — Form,  spherical;  color,  rich,  dark  purple  on  ripening; 
surface,  warty,  very  rough:  rind,  thick  and  granular,  forming  a 
firm,  shell-like  covering.  (PL  X,  fig.  1.)  Total  weight,  12  ounces  to 
1  pound;  flesh,  yellow,  varying  to  green  toward  the  rind;  texture, 
buttery  and  without  fiber;  flavor,  rich  and  nutty.  The  seed  is  small 
to  meclium,  tight  in  the  cavity,  nearly  spherical  in  form,  covered 
with  two  tight-fitting  coats;   weight,  about  2  ounces.      Season   of 


^The  accession  numbers  under  which  most  of  the  varieties  have  been  propagated  at 
the  station  are  also  given  in  the  outline  and  descriptions. 


20  BULLETIN    51,   HAWAII   EXPERIMENT   STATION. 

maturity  of  fruit,  from  November  to  April,  varying  somewhat  ac- 
cording to  elevation. 

WILDER. 

The  seed  of  the  original  tree  of  the  Wilder  (:N'o.  4540)  (PI.  IV, 
fig.  1)  was  obtained  by  Gerrit  P.  Wilder  from  F.  W.  Macfarlane, 
who  lived  on  the  Wiedemann  place,  now  known  as  the  Macdonald 
Hotel.     Mr.  Wilder  planted  the  small  seedling  tree  in  his  private 

frden  at  1930  Ualakaa  Street,  in  Makiki,  Honolulu,  in  1900.  Al- 
ough  the  tree  grew  vigorously  for  eight  years  and  bore  fruit  abun- 
dantly, it  gradually  began  to  show  signs  of  unsatisfactoi-y  soil  con- 
ditions, and  new  trees  were  propagated  from  it  by  inarching  on 
seedling  rootstocks.  The  variety  was  maintained  through  the  in- 
arching progeny  from  which  there  has  been  developed  a  large 
number  of  varieties.  When  grown  in  proper  environment  the  Wilder 
is  a  vigorous  tree  of  rather  upright  growth  and  produces  an  abun- 
dance of  fruit  of  excellent  quality.  The  variety  is  easily  propa- 
gated by  budding.  The  fruit  ripens  during  October,  November,  De- 
cember, and  January. 

Fruit. — Form,  almost  spherical  or  slightly  elongated;  color,  olive 
green;  rind,  surface  slightly  undulated,  so  thick  as  to  be  shell-like; 
weight,  IJ  pounds;  flesh,  yellow,  tinged  to  green  next  to  the  rind, 
nutty  in  flavor,  and  free  from  fiber ;  seed,  larger  than  the  ideal,  tight 
in  the  cavity,  covered  with  skin  but  a  perfect  freestone.  Keeping 
qualities  of  the  fruit  are  very  good. 

LAHI. 

The  original  tree  of  the  Lahi  avocado  (No.  4926)  was  a  cross  be- 
tween the  Wilder  and  the  West  Indian,  produced  in  1914,  and  the 
seedling  set  at  "  Esbank,"  the  old  Wilder  home,  60  Judd  Street. 
Honolulu.  It  began  to  fruit  lightly  in  its  sixth  year.  It  is  carrying 
a  good  crop  at  present  (1923).  Each  fruit  grows  on  a  long  stem 
and  matures  in  November  and  December. 

Fruit, — Form,  oblong  oval;  weight,  18  ounces;  color,  green  at 
maturity  with  whitish-green  specks  on  entire  surface.  Surface, 
slightly  bumpy,  smoothed  over ;  rind,  about  one-sixteenth  inch  thick, 
leathery,  separating  from  flesh  easily  at  maturity.  The  flesh  is  yel- 
low, smooth,  free  from  fiber,  rich,  oily,  and  of  nutty  flavor.  The 
seed  averages  about  3  ounces,  is  tight  in  the  cavity ;  cotyledons,  cov- 
ered with  two  tight  coats  which  adhere  to  seed  on  removal  from 
fruit. 

CALABASH. 

The  Calabash  avocado  (No.  4674)  is  growing  in  the  yard  of  S.  G. 
Wilder,  where  it  was  planted  in  1914.  (PI.  IX,  fig.  1.)  It  is  a 
vigorous  tree  of  medium  size  and  began  to  fruit  in  its  sixth  year. 
Trees  of  the  variety  have  been  propagated  by  budding.  Its  desir- 
able flavor  indicates  that  this  sort  is  worthy  of  cultivation. 

Fruit. — Form,  almost  oval,  but  slightly  narrowing  at  stem  end, 
giving  the  fruit  a  calabash  shape.  In  size  it  is  medium,  weighing 
about  a  pound;  color,  dull  green,  darkening  almost  to  black  about 
the  stem  end  upon  maturing;  rind,  thick  and  shell-like,  surface  un- 
dulating to  roughness  around  the  stem  end ;  the  flesh  is  very  yellow, 
varying  to  green  near  rind:  slightly  fibrous;  rich  and  nutty  in 
flavor;  seed,  medium  to  large,  about  3  ounces  in  weight  and  fits 
tightly  in  the  cavity. 


Bui.  51,  Hawaii   Agr.  Expt.  Station. 


PLATE   VII. 


Fig.  I. — ILIALU  (Ace.  No.  4696). 

A  splendid  keeper.    Will  remain  on  the  tree  for  a  considerable  time  after  maturing  enough  to 

pick. 


Fig.  2.— The  Cogkett  (Acc.  No.  4817). 

This  large  purple  avocado  is  a  cross  between  the  Case  and  the  West  Indian.  The  fruit  indicates 
characters  of  size,  reduced  thickness  of  rind,  and  a  seed  slightly  loosened  in  the  cavity,  all  of 
the  latter  race. 


Bui.  51,  Hawaii    Agr.  Expt.  Station. 


Plate  VI If. 


Fig.  I. — Lehua  (Acc.  No.  4695). 

Fruit  is  large  and  has  many  points  in  its  favor.    The  percentage  of  edible  pulp  particularly  is 

high. 


Fig  2.— The  Holt  (Acc.  No.  4819). 

This  fruit  is  the  favorite  variety  of  Valentine  Holt,  horticulturist,  Honolulu.     It  is  a  second 
generation  from  the  variety  Macdonald. 


Bui.  51,  Hawaii   Agr.  Expt.  Station. 


PLATE   IX. 


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Bui.  51,  Hawaii   Agr.  Expt.  Station. 


Plate  X. 


Fig.  I.— The  Macdonald  ^Acc.  No.  4191). 

The  thick,  shell-like  rind  of  this  fruit  is  a  strong  protective  feature  against  insect  pests:  it  also 
greatly  prolongs  the  period  of  time  that  the  fruit  may  be  held  on  the  market. 


Fig.  2.— Kinau   (Acc.  No.  4675). 

A  new  variety  of  which  the  Macdonald  is  a  grandparent.     The  high  quality  of  the  fruit 
indicates  that  it  is  one  of  promise. 


THE    GUATEMALAN   AVOCADO   IN"    HAWAII.  21 

ILIALU. 

The  Ilialu  avocado  (No.  4696)  (PL  VII,  fig.  1)  was  planted  at 
"Esbank,--  60  Jiidd  Street,  Niiuanii  Valley,  Honolulu,  in  1914.  The 
tree,  while  not  large,  is  healthy  and  vigorous  and  produced  its  first 
crop  at  7  years  of  age  (1921).  The  fruit  is  well  distributed  on  the 
tree  and  does  not  fall  easily  after  it  matures. 

Fruit. — Pyrif orm  in  shape ;  weight,  13  ounces  to  1  pound ;  surface 
color,  dark  green  when  the  fruit  is  ripe ;  rind,  thick,  rough,  granular 
shell:  flesh,  fiber  free,  firm,  and  fine  grained;  flavor,  good;  seed,  of 
medium  size,  tight  in  cavity;  keeping  and  shipping  qualities, 
excellent. 

LEHUA. 

The  Lehua  avocado  (No.  4695)  (PI.  VIII,  fig.  1)  grows  on  the 
residential  propert}^  of  S.  G.  Wilder  at  "  Esbank."  The  tree  pro- 
duced its  first  fruit  in  1921,  at  5  years  of  age,  is  vigorous  and 
healthy,  and  gives  considerable  promise  as  a  new  variety. 

Fruit. — Form,  oval;  size,  medium;  weight,  1  to  IJ  pounds;  color, 
dark  mahogany;  surface,  irregular,  undulated  to  bumpy,  each  fruit 
usually  possessing  a  characteristic  radiating  scar.  The  rind  is 
rather  thick  and  shell-like,  varying  from  one-eighth  to  three- 
sixteenths  inch  in  thickness  and  is  very  coarse  and  granular.  The 
flesh  is  fiber  free,  yellow,  buttery,  and  of  a  pleasing  nutty  flavor. 
The  seed  is  covered  with  two  tight-fitting  coats  and  is  tight  in  the 
cavity. 

KINAU. 

The  Kinau  avocado  (No.  4675)  (PL  X,  fig.  2)  grows  in  the  yard 
of  S.  G.  Wilder,  and  it  produced  its  first  crop  in  1921,  is  healthy,  and 
gives  much  promise  as  a  new  variety. 

Fruit. — Form,  oval;  color,  bright  green;  surface,  very  irregular; 
rind,  thick  and  shell-like ;  weight,  14  ounces  to  1  pound ;  flesh,  fiber 
free,  light  greenish  yellow,  and  of  fairly  rich  flavor;  weight  of 
seed,  about  2  ounces;  two  coats  tight  in  cavity;  keeping  quality,  very 
good. 

NUTMEG. 

The  Nutmeg  avocado  (No.  4076)  (PL  III,  fig.  2)  was  grown  at 
the  experiment  station  in  1907  under  accession  No.  1035. 

Fruit. — Form,  nearly  spherical,  slightly  oval  to  pyrif  orm;  color, 
dull  green;  surface,  very  rough,  particularly  near  the  stem  end; 
rind,  medium  in  thickness,  tough  and  hard ;  total  weight,  26  ounces 
or  more;  flesh,  light  yellow,  tinged  to  green  near  rind;  texture, 
smooth  and  fine  grained  with  very  little  fiber;  flavor,  excellent; 
seed,  large,  tight  in  cavity,  and  weighs  about  6^  ounces.  (For 
analj'ses,  see  table,  p.  16.) 

BEARDSLEE.13 

The  original  Beardslee  avocado  (No.  4075)  (PL  IV,  fig.  2),  more 
commonl}^  known  as  "  Abies,''  was  grown  from  a  seed  of  the  Mac- 
donald  variety.  It  was  planted  December  18,  1911,  by  L.  C.  Abies 
in  his  home  gardens  at  1627  Kewalo  Street,  Honolulu.  It  is  known 
to  have  produced  a  crop  of  fruit  within  four  years  after  planting. 
The   season  of  maturing  the  fruit  varies  from  late  fall  to  early 

"Originally,  but  erroneously,  spelled  "  Beardsley." 


0 
22  BULLETIN    51^    HAWAII   EXPERIMENT   STATION. 

winter.  The  tree  is  of  upright  and  rather  dense  habit,  a  regular 
and  prolific  bearer.  Many  trees  of  this  variety  have  been  propagated 
by  budding.  The  fruit  is  the  largest  and  most  perfect  of  aU  the 
Guatemalan  varieties  that  have  come  under  observation  at  the  sta- 
tion. It  has  been  referred  to  by  good  authority  as  the  best  of  its 
race  in  Hawaii.  The  variety  was  named  Beardslee  in  1919  in  honor 
of  the  man  who  introduced  the  seed  of  the  parent  tree  into  Hawaii, 
but  it  seems  to  be  generally  known  locally  as  the  Abies. 

Fruit. — Form,  oval  to  pyriform;  weight,  \\  to  24  pounds;  color, 
purple  on  the  surface  when  ripe ;  rind,  thick  and  shell-like,  granular, 
woody,  and  with  a  pebbled  outer  surface.  The  flesh  is  yellow  tinged, 
with  green  next  to  the  rind;  texture,  fine  grained  with  a  trace  of 
fiber  at  the  base;  flavor,  rich  and  nutty;  seed,  small  and  tight,  or 
nearh'  so,  in  the  cavity ;  weight  of  seed,  2  to  2J  ounces ;  total  edible 
portion  averages  about  71  per  cent. 

HALEY. 

The  Haley  avocado  (No.  4821)  (PI.  Y,  fig.  2)  is  a  seedling  of 
the  Guatemalan  race  which  was  planted  in  Hawaii  in  1913.  It 
is  grown  on  the  ranch  of  Haley  Bros.,  Pupukea,  Oahu.  The 
trees  are  prolific,  coming  into  bearing  about  the  third  or  fourth 
year,  and  producing  fruits  in  clusters.  The  fruit  ripens  at  lower 
elevations  in  November  and  December.  Many  trees  have  been 
propagated  from  this  variety  by  W.  H.  Haley,  2621  East  Manoa 
Road,  Honolulu. 

Fruit. — Size,  6  inches  in  length,  4-|  inches  in  diameter;  weight,  35 
to  40  ounces.  Form,  oval  to  obovate ;  rind,  thick,  tough,  and  granu- 
lar ;  surface,  rough,  green  in  color,  with  a  slight  purplish  tinge  upon 
fully  ripening:  flesh,  fiber  free,  creamy  yellow;  flavor,  rich,  nutty; 
seed,  small  to  medium  in  size,  and  fits  tightly  in  the  cavity. 

HOLT. 

The  Holt  avocado  (No.  4819)  (PL  VIII,  fig.  2)  is  growing  in 
the  rear  of  the  residence  at  the  northwest  corner  of  the  intersec- 
tion of  Makiki  and  Lunalilo  Streets,  Honolulu.  It  was  about  7 
years  old  in  1921,  in  healthy  condition,  and  gives  promise  of  being 
a  good  winter-bearing  variety. 

Fruit. — Form,  varying  from  oval;  color,  shiny  green  when  ripe; 
surface,  undulated  but  smooth;  rind,  thick,  firm,  and  shell-like; 
total  weight,  about  1  pound  3  ounces;  flesh,  fiber  free,  yellow,  firm, 
buttery,  and  of  a  very  good,  nutty  flavor;  seed,  rather  large,  weigh- 
ing about  5  ounces.    This  variety  is  well  worthy  of  bud  propagation. 

TOWSE. 

The  Towse  avocado  (No.  4818)  (PI.  IX,  fig.  2)  is  growing  on  the 
south  side  of  the  residence  of  E.  Towse,  1105  Eleventh  Avenue, 
Kaimuki,  Honolulu.  In  1922  the  tree  was  large  and  spreading, 
and  reached  a  height  of  about  45  feet.  It  is  a  prolific  bearer  and 
produces  large  attractive  fruit  which  matures  in  November  and 
December. 

Fruit, — Form,  pyriform;  size,  large,  weighing  about  26  ounces; 
color,  purple;  rind,  three-sixteenths  inch  in  thickness,  bumpy,  usually 
bearing  the  tj'pical  radiating  scar-like  marking;   flesh,  fiber  free. 


THE   GUATEMALAN   AVOCADO   IN   HAWAII.  23 

light  yellow,  and  of  good  flavor;  seed,  large,  weight  6J  ounces,  and 
fits  tightly  in  cavity.     (For  analyses,  see  talble,  p.  16.) 

BON. 

The  Bon  avocado  (No.  4820)  (PL  VI,  fig.  2)  is  supposedly  a 
seedling  of  the  Macdonald.  It  grows  in  the  yard  of  E.  Towse.  The 
seed  was  given  to  and  planted  in  1908  by  S.  D.  Koki,  former  owner 
of  the  Towse  property.  At  present  the  tree  is  about  45  feet  high 
and  of  rather  upright  form.  It  is  very  proHfic,  often  producing 
1,000  fruits  in  a  season.  The  fruit  ripens  in  November  and  in  early 
December.  Judging  from  the  appearance  of  the  foliage  and  fruit, 
it  is  thought  that  the  tree  is  a  hybrid  between  the  Guatemalan  and 
the  West  Indian  type  of  avocada. 

Fruit. — Form,  oval:  size,  medium;  weight,  about  23  ounces; 
color,  shiny  green ;  rind,  medium  in  thickness,  rather  smooth  on  sur- 
face; flesh,  fiber  free,  rich,  light  yellow,  rather  dry  but  appetizing; 
seed,  large,  weighing  about  5J  ounces.  (For  analvses,  see  table, 
p.  16.) 

KALUA.i- 

The  Kalua  avocado  (No.  3413)  (PI.  V,  fig.  1)  is  reported  to  be  in 
fruit  almost  every  month  of  the  year.  A  number  of  seedlings  pro- 
ducing fruit  of  fine  quality  have  been  grown  from  the  seed  of  this 
tree.    Both  original  and  progeny  are  winter  bearing. 

Fruit. — Pyriform  in  shape,  shiny  green  in  color,  turning  lighter 
green  on  ripening;  averages  about  12  oimces  in  weight.  The  rind 
is  thick,  smooth  outside  and  granular  within.  The  flesh  is  light  yel- 
low, averages  about  three-fourths  inch  in  thickness,  is  butteiy,  and 
of  a  fairly  good  flavor.  This  fruit  is  a  splendid  keeper.  The  seed 
is  of  medium  size,  weighing  about  2  omices,  and  is  tight  in  the  cavity. 

CASE. 

The  Case  avocado  (Xo.  4705)  (PL  VI,  fig.  1)  was  planted  in  the 
garden  of  D.  H.  Case,  at  Wailuku,  Maui.  The  tree  has  always  been 
vigorous  and  prolific,  flowering  in  February  and  March  and  fruiting 
from  October  tO'  March.  The  fruit  varies  considerably  from  the 
Kalua  avocado,  having  characters  that  are  superior  to  the  latter 
and  some  fruits  that  curve  too  much.  The  Case  avocado  in  its  third 
year  produced  25  fruits ;  in  its  fourth  year,  35  fruits ;  and  in  its  fifth 
and  twelfth  yeai*s,  hea\y  crops.  No  record  has  been  kept  of  its  yield 
from  the  fifth  to  the  twelfth  year.  Seedlings  fi^om  the  Case  have 
developed  fruit  of  fairly  good  quality  and  showed  veiy  little  of  the 
curved  or  pyriform  shape. 

Fruit, — ^Long,  curved  neck,  pyriform;  size,  7  inches  in  length; 
color,  shiny  dark  green;  sirface,  varying  from  smooth,  imdulated, 
to  wrinkled  at  the  neck  near  the  stem;  rind,  one-sixteenth  inch  or 
more  in  thickness,  forming  a  gi^anular  shell ;  average  weight,  between 
16  and  18  ounces.  Flesh,  light  yellow,  shading  to  pale  yellow  near 
the  rind.  Texture,  buttery  without  fiber ;  flavor,  nutty,  approaching 
closely  that  of  the  ideal ;  seed,  small  considering  the  size  of  the  fruit, 
and  weighs  about  1^  ounces,  fits  tightly  in  the  cavity  and  is  a  free- 

^*  Sometimes  misspelled  "  Kailua." 


24  "       BULLETIN    51,    HAWAII   EXPERIMENT   STATION. 

stone.    Case  is  one  of  the  best  to  propagate  at  present,  because  it  has 
a  long  winter- fruiting  period  and  is  prolific  and  vigorous. 

COCKETT. 

The  Cockett  avocado  (No.  4817)  (PI.  VII,  fig.  2),  grown  by  Mrs. 
Pia  Cockett,  Wailuku,  Maui,  fruited  in  its  third,  fourth,  and  fifth 
years.    The  fruit  matures  in  November  and  December. 

Fruit. — Fonn,  oval  to  pyriform:  size,  large,  weighing  2  pounds; 
color,  purple  with  greenish  cast ;  surface  undulated  but  smooth;  rind 
one-eighth  inch  in  thickness,  tough,  and  leathery;  flesh,  fiber  free, 
smooth;  color,  yellow  tinged  with  green;  flavor  good;  seed,  large, 
weighing  4^  ounces,  almost  filling  cavity. 

FUERTE. 

The  Fuerte  avocado  (No.  4559)  originated  at  Atlixco,  Puebla, 
Mexico.  Although  it  is  generally  classed  with  the  Guatemalan 
varieties,  it  is  now  believed  to  be  a  natural  hybrid  between  the 
Guatemalan  and  Mexican  races.  The  variety  produces  its  fruit 
during  the  winter  months.  Bud  wood  of  the  variety  has  on  several 
occasions  been  introduced  into  Hawaii  by  the  station  through  the 
United  States  Department  of  Agriculture,  and  probably  also  by 
W.  D.  Baldwin  of  Haiku,  Maui.  Trees  of  the  several  introductions 
are  now  to  be  found  in  various  parts  of  the  Territory.  Trees  in  the 
orchard  of  C.  Miller,  cooperator  of  Kaneohe,  Oahu,  produced  some 
fruit  in  December,  1922.  Judging  from  its  hardiness  in  California, 
it  is  thought  that  the  tree  will  make  its  best  growth  in  the  agricul- 
tural areas  at  higher  altitudes  in  the  islands.  It  is  a  favorite  with 
many  growers  in  California  on  account  of  its  hardiness  and  high- 
grade  fruit. 

Fruit. — Form,  pyriform  to  oblong,  not  necked;  size,  medium; 
weight,  10  to  16  ounces;  length,  4  to  4J  inches,  greatest  breadth  2^ 
to  2f  inches;  stem,  inserted  obliquely  in  a  small  shallow  cavity; 
surface  pebbled,  somewhat  wrinkled  around  the  stem  end ;  color,  dull 
green  with  numerous  small  yellow  dots;  rind,  about  one-sixteenth 
inch  in  thickness,  pliable  and  leathery  in  texture ;  flesh,  rich  creamy 
yellow  in  color,  greenish  near  the  rind;  veiy  rich  flavor;  quality 
excellent ;  seed,  small,  tight  in  cavity,  seed  coats  closely  surrounding 
the  cotyledons. 

TAFT. 

The  Taft  avocado  (No.  4565)  originated  as  a  seedling  at  Orange, 
Calif.,  and  was  first  propagated  in  1912.  Several  introductions  have 
been  made  into  Hawaii,  but  it  is  not  known  as  yet  what  their 
productiveness  will  be. 

Fruit. — Form,  broad,  pyriform,  slightly  necked;  size,  medium  to 
large;  weight,  14  to  24  ounces;  length,  5  to  5^  inches;  greatest 
breadth,  3|  inches;  surface,  undulating  to  roughened  around  the 
stem  end ;  color,  deep  green  with  numerous  yellow  dots ;  rind,  thick, 
granular,  and  rather  pliable;  flesh,  firm,  smooth,  light  yellow  in 
color:  flavor,  rich  and  pleasant,  quality  very  good;  seed,  medium 
size,  tight  in  cavity  with  seed  coats  adhering  closely.  Season  for 
ripening  varies  from  summer  to  late  fall,  depending  upon  locality. 

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